On Sun, Oct 2, 2016 at 7:19 PM, Marek Vasut marex@denx.de wrote:
/**
- drm_fb_cma_extract_and_attach_fence() - Extract fence from plane and
attach to planestate
- @plane: Which plane
- @state: Plane state attach fence to
- If the plane fb has an dma-buf attached, fish out the exclusive
- fence and attach it to plane state for the atomic helper to wait
- on.
*/
That choice of color is ok with me too, but then you need to have a pile of text to explain where it should be used (i.e. directly as the prepare_fb hook).
There can be more stuff in the prepare_fb hook though.
There's 3 things prepare/cleanup_fb should do: - pin/upin the backing storage. CMA memory is always pinned, so nothing to do. - setup/tear down iommu mappings: Already done when allocating CMA memory, again nothing to do. - grab fences in prepare.
So for plain cma drivers this hook is indeed the complete implementation they need for prepare_fb. I guess you could mention in the kernel-doc that cma based drivers don't need a cleanup_fb, hence why there is none. -Daniel